In fact in the original Greek the first and last words in this verse are the same and one Greek word: Pneuma

Joh 3:8The wind bloweth where it listeth, and thou hearest the sound thereof, but canst not tell whence it cometh, and whither it goeth: so is every one that is born of the Spirit.

Now on Dominus the Britannica says:

dominus, pluralDomini, inancient Rome, “master,” or “owner,” particularly of slaves. The name became the official title for the emperor, beginning withDiocletian, who reigned fromad284 to 305; and thus he and his successors are often referred to as thedominate (dominatus), as contrasted with the earlier principate (principatus) of Augustus and his successors. Some earlier emperors, such as Caligula (reignedad37–41), however, also had used the title. By Trajan’s day it was the common form of address to the emperor.
In the Latin church, Dominus was used as the equivalent of the Hebrew Adonai and the Greek Kyrios, to refer to the Christian God.Dominusin medieval Latin referred to the “lord” of a territory or the overlord of a vassal. It was later used as a respectful form of address (Spanishdon,Portuguesedom) and for the clergy (Italiandon).